Fatal error: Uncaught Error: Class "Tests\TestCase" not found in /home/techguruuico/public_html/mailuai.com/vendor/mettle/sendportal-core/tests/Feature/API/SubscribersControllerTest.php:15 Stack trace: #0 {main} thrown in /home/techguruuico/public_html/mailuai.com/vendor/mettle/sendportal-core/tests/Feature/API/SubscribersControllerTest.php on line 15